Temperature dependence of the ionic conductivity in Li_(3x)La_(2/3-x)TiO_(3): arrhenius versus non-Arrhenius

Abstract

We report on the temperature dependence of the ionic conductivity at low temperatures in the crystalline lithium ionic conductor Li_(0.18)La_(0.61)TiO_(3). Time domain measurements of the electric modulus have been performed to investigate ion dynamics in the frequency range 1025 – 102 Hz and for conductivity values in the range 10214 – 1028 S/cm. Ionic conductivity shows an Arrhenius temperature dependence below 300 K and down to 120 K, in contrast to the non-Arrhenius behavior found at higher temperatures, demonstrating that the temperature dependence of ionic conductivity in Li_(0.18)La_(0.61)TiO_(3) cannot be described by a Vogel–Fulcher–Tamman law.